future proofing cooling issues

[vardenafil]

hi guys. happy turkey day! I have a stock 350 sbc in my a/c truck. it overheats in city traffic but not on the highway. i read that on the forums that would be a fan flow issue not radiator issue. i replaced the thermostat w/ a high flow 180 stat last week. i have a severe duty clutch fan coming in sometime after the holidays. i dont know if that will solve the issue though since the current clutch fan looks brand new. hopefully that will take care of me for awhile. my truck is currently the stock 170 horsepower truck. eventually i want to buy a complete torquer kit from summit or the likes to get it close to 270 horsepower. where i live it gets up to 120 degrees several times a year. we are over 100+ degrees almost half the year. so i need to future proof my cooling needs. I was thinking about replacing the radiator now seeing how the radiator looks stock? would a new 4 core stock radiator suffice? Do i need to go aluminum? or can/should i drop in a longer radiator such as a bbc 454 radiator to help cool?

[dagnabbitt]

How is your fan shroud? How many blades are the fan?

You might benefit from a new rad, but good to eliminate a few other variables.

[Stocker]

Originally Posted by dagnabbitt

How is your fan shroud? How many blades are the fan?

Exactly where I would start. Also does the fan fit properly in the shroud? What is the diameter of your fan?
Is your existing fan clutch standard duty or heavy duty? A few pics would help.

[Rust_never_sleeps]

Does the fan you have now spin freely, or is there some resistance?
Shroud is always worth a look too, as noted above

[dagnabbitt]

Also: although you say the truck is stock, have you had the truck for long? Would you be able to say it has been worked on by someone who knows what they are doing, or did the last guy seem clueless.

I once had a truck that the previous owner said just needed a new rad for sure: he knew this because he had eliminated all of the other variables... he said it actually ran hotter after he installed a brand new fan. I noticed that he had put it on backwards, I flipped it around and it was fine.

[vardenafil]

The fan shroud looks decent. There is a stock I assume 7 blade fan attached. I’m not too sure what service level the clutch fan is. It looks brand new. No dirt or anything on the fan still shinny. I’ve had the truck a year now. But who knows what the previous owner did

[Stocker]

Originally Posted by vardenafil

I’m not too sure what service level the clutch fan is.

https://www.haydenauto.com/en/produc...-types/thermal

Standard duty: Identified by a smooth steel faceplate & thermal spring assembly on the front side.



Heavy duty: Identified by finned aluminum faceplate and thermal spring on the front. This is a Hayden #2747 which is what I have on my K20.



Severe duty: Land and groove design with up to 72 sq. in. of working area.
Larger working surface provides cooler running and longer life expectancy.
Thicker body and deep finned faceplate dissipates more heat.

[HO455]

How the fan sits inside the shroud is also important. Too far inside or outside of the shroud is bad for air flow through the radiator. See arrow in picture for how the fan should be located and notice how close the fan blade is to shroud.

Have you taken a look inside the radiator? You may have to drain some coolant to get a good look. Do you see build up on the tubes?

[Myself]

I'm sure some folks will hate this answer BUT........twice now I've done the cheapo 3 row aluminum overseas radiators from Ebay. The ones that come with an aluminum shroud and twin electric fans. Wire up 3 ice cube relays in the "LS" high and low style setup and a Volvo double temp switch (needs a metric adapter to thread into the intake or water pump) and don't ever worry about overheating again.

[Sheepdip]

Originally Posted by Myself

I'm sure some folks will hate this answer BUT........twice now I've done the cheapo 3 row aluminum overseas radiators from Ebay. The ones that come with an aluminum shroud and twin electric fans. Wire up 3 ice cube relays in the "LS" high and low style setup and a Volvo double temp switch (needs a metric adapter to thread into the intake or water pump) and don't ever worry about overheating again.

Not Me!
I like originality for the most part but I'm also all about trouble free function.

When Otis needed a radiator I installed a Champion system to cool up to 1000 hp. With the hot valley summers running A/C, towing trailers, high amperage alternator, etc. I have plenty of cooling in 100+ degree heat, stop n go city traffic, windows up and ice cold A/C blowing in my face.

I currently run 3 Champion Systems all with A/C, all with thermostatic controlled electric fans, one has been in for over 20 years and never a hint of a problem.

Bottom line it's your truck so do what satisfies you.

[PbFut]

I have the champion setup. Works very good in the so cal inland heat. Hill and many days over 100 with ac. But the duel fans are hard on the electrical system and requires some modifications if you want to correctly wire to the main splice so the stock battery guage registers correctly without pinning. Simply wiring to the fuse link block will work but render the battery guage nearly useless.
I also added a remote oil filter with 2quart filter to up capacity and a large oil cooler. That helps a lot. Having to do over, I would try to get the oem shroud and fan to work rather than the electric fans. One last note on the champion fans. Do not use their connectors. They do not stay connected tightly and will kill the fan quickly with a low amperage condition in the high heat of summer. I killed two fans thinking I messed up t
Plugging in only to have the second one fail few weeks later. I removed connectors and soldered. No issues since. I also added an additional relay that triggers when the ac compressor triggers and coolant is below trigger temp. If you don't have ac and you don't care about battery guage working correctly, wiring the fans is simple. But if you want everything correct, the wiring takes some thought, planning and at least a full day to execute.

[LS short box]

Not a SBC but on my LS swaps I run the biggest alum radiator I can fit. On my 68 it was a Afco generic LS swap radiator. 16" Spal electric fan which on some of my LS swaps ran off a switch in the radiator or by the ECM. You can get the Afco rad configured for a SBC also. IIRC I bought from Speedway Motors.

[don t. - 72gmc]

As others have said, do the easy stuff 1st.
Thermostat in the proper direction.
Fan, shroud, fan clutch working as it should.
Maybe R&R the lower rad hose if old and soft.

Im not a fan of internet type purchases. I took my old rad out to a local radiator shop. Had him recore it to factory specs. I then knew, it would fit w/no monkeying around. This solved my overheat issue.

HTH...Don.

[Sheepdip]

Originally Posted by don t. - 72gmc

As others have said, do the easy stuff 1st.
Thermostat in the proper direction.
Fan, shroud, fan clutch working as it should.
Maybe R&R the lower rad hose if old and soft.

Im not a fan of internet type purchases. I took my old rad out to a local radiator shop. Had him recore it to factory specs. I then knew, it would fit w/no monkeying around. This solved my overheat issue.

HTH...Don.

All valid points to check off the list.

Here in Kalifornia an acid bath for a radiator does not exist, and has not for quite some time, so a good rebuild/re-core on a original brass radiator no longer exist.

[54blackhornet]

For anyone who is interested there is an old style radiator shop located in Walla Walla Washington. Grieners is the name. Been in operation since the 30/40’s. I have had numerous radiators rebuilt by them. Excellent work every time..

[Rust_never_sleeps]

Pankey's in Hayward, CA has been doing great work for about 80 years. 510-581-6804

[don t. - 72gmc]

I'll give a shout out to Tim at Revcore Radiators in Woodstock, Ill-noise. I've had many items repaired by Tim well over 30 years.

[vardenafil]

https://ibb.co/DKQ6dQh
https://ibb.co/R9wftVz
https://ibb.co/m8zDjbF
https://ibb.co/DKnRMZn

Sorry it took so long for me to respond. I didn’t mean to ask for advice and then abandon my post. I got hit with pneumonia and covid and haven’t been up to much the last 10 days or so.still not at 100 percent but doing better.

From what I can tell the fan clutch looks brand new as well as the fan shroud. The fan shroud is fit properly no gaps etc. the fan clutch appears to be a hayde 2747 which would be the correct medium duty fan clutch. I don’t know if the severe duty clutch would be worth the investment. There is no play or wobble in the fan clutch. If I spin the fan by hand the fan immediately stops. So I think the fan clutch is good? The thermostat is installed correctly going the right way. The upper radiator hose does not seem to be a molded hose it looks like it is a straight hose bent to fit but it is not kinked by any means. The lower hose feels solid. The only thing that might be helpful when I overheated last time the temp gauge was about 220. That seems kinda low? Thanks in advance for any advice

[vardenafil]

Originally Posted by dagnabbitt

Also: although you say the truck is stock, have you had the truck for long? Would you be able to say it has been worked on by someone who knows what they are doing, or did the last guy seem clueless.

I once had a truck that the previous owner said just needed a new rad for sure: he knew this because he had eliminated all of the other variables... he said it actually ran hotter after he installed a brand new fan. I noticed that he had put it on backwards, I flipped it around and it was fine.

How do I tell if my fan blades are on backwards?

[HO455]

Sometimes they have a F or FRT stamped on them to indicate the front of the fan.

Post a photo and maybe one of the folks here can answer that for you.

[Steeveedee]

On the plate that mounts to the fan clutch, the blades are on the radiator side.

[vardenafil]

here is the pic I could get of the fan blades position relative to the clutch. https://ibb.co/m8zDjbF

[72SB]

get a 18" 7 blade fan

[Stocker]

Originally Posted by 72sb

get a 18" 7 blade fan

x2!

[vardenafil]

The truck already has a seven blade 18 inch fan.